This application relates generally to disc drives and actuator arms for disc drives.
Disc drives are used in workstations, laptops and personal computers to store large amounts of information in a readily accessible form. Typically, a disc drive includes a magnetic disc, which is rotated at a constant high speed by a spindle motor. The disc surfaces are divided into a series of concentric data tracks. Each data track can store information as magnetic transitions on the disc surface.
A disc drive also includes a set of magnetic transducers that are used to either sense existing magnetic transitions during a read operation or to create new magnetic transitions during a write operation. Typically, each magnetic transducer is mounted in a head, which is mounted onto one end of an actuator arm. A pre-amplifier, which amplifies read signals generated by the head, is connected to an outer surface of the actuator arm via a flexible element, which can accommodate movement of the head/actuator arm during operation. The actuator arm serves to selectively position the head over a particular data track to either read data from the disc or to write data to the disc.
Typically, the actuator arm is driven by a voice coil motor. The magnetic transducer, which is mounted in a head, is present at one end of an actuator arm, which extends radially outward from a substantially cylindrical actuator body. The actuator body is movably supported by a ball bearing assembly known as a pivot bearing assembly. The actuator body is parallel with the axis of rotation of the disc. The magnetic transducer, therefore, moves in a plane parallel to the disc surface.
The voice coil motor typically includes a coil, which is mounted on a surface of the actuator arm at an end opposite to the head. This coil is permanently immersed in a magnetic field resulting from an array of permanent magnets, which are mounted to the disc drive housing. Application of DC current to the coil creates an electromagnetic field, which interacts with the permanent magnetic field, causing the coil to move relative to the permanent magnets. The voice coil motor essentially converts electric current into mechanical torque. As the coil moves, the actuator arm also moves, causing the head to move radially across the disc surface. Control of the actuator arm movement is accomplished via a closed loop servo system.
Conventional actuator arms have been formed from homogenous metals, such as aluminum. In these actuator arms, the voice coil is attached to an exterior surface of the metal arm via an adhesive or some other bonding means. Other components of an actuator assembly, such as the Printer Circuit Cable (PCC) and the Flex On Suspension (FOS), are also connected to an exterior surface of the actuator arm. Such a construction has many mechanical and electrical disadvantages. First, the construction of a conventional actuator arm/voice coil assembly requires numerous individual components, which have to be manufactured separately and then assembled separately using an adhesive or some other bonding means. Further, due to the number of individual components in a conventional actuator assembly, such as the head and the pre-amplifier, a minimum number of interconnects between the individual components is necessary to provide electrical conductivity between the individual components.
Accordingly, there is a need in the art for an integrated actuator assembly for disc drives, wherein the number of individual components is minimized, and the number of interconnects between components is minimized. Further, there is a need in the art for an actuator assembly, which can be manufactured at low cost and high production without the need for many and/or multiple conventional process steps.
Embodiments of the present invention address some of the difficulties and problems discussed above by the discovery of an integrated actuator assembly comprising a low cost actuator arm, wherein one or more components of the actuator assembly are incorporated into the actuator arm. The integrated actuator assembly of one embodiment of the present invention minimizes the number of individual components and the number of interconnects between components. Further, the integrated actuator assembly of this embodiment of the present invention is made using a low cost, high output manufacturing process without the need for many conventional process steps, such as an adhesive bonding step.
Accordingly, an embodiment of the present invention is directed to an integrated actuator assembly comprising a low cost actuator arm, wherein one or more components of the actuator assembly are incorporated into the actuator arm.
Another embodiment of the present invention is further directed to a method of making an integrated actuator assembly comprising incorporating one or more electrical components of an actuator assembly into an actuator arm. The one or more electrical components may include a voice coil, one or more conductors, and other components, which are conventionally attached to outer surfaces of an actuator arm.
Embodiments of the present invention are also directed to a disc drive system comprising (a) at least one disc, and (b) at least one actuator arm, wherein the at least one actuator arm contains one or more components of an actuator assembly within exterior surfaces of the actuator arm.
Embodiments of the present invention may also be directed to a method of reading data from a disc or writing data to a disc using a disc drive system comprising (a) at least one disc, and (b) at least one actuator arm, wherein the at least one actuator arm contains one or more components of an actuator assembly within exterior surfaces of the actuator arm.
These and various other features as well as advantages, which characterize embodiments of the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.